第3题: [单项选择]You ______ yesterday if you were really serious about the job. A. ought to come B. ought come C. ought have come D. ought to have come 参考答案:D 答案解析:考查情态动词及其时态。Ought to do sth应该做某事。排除选项B和C。条件从句的时态为过去时,主句有yesterday,说明是过去发生的事情。情态动词后用完成时表示已发生的动作。选项D是正确